EFFECTS OF SOME METABOLIC CO-FACTORS AND INHIBITORS ON TRANSMITTER RELEASE AND UPTAKE IN ISOLATED ADRENERGIC NERVE GRANULES

Various nucleotides and metabolic inhibitors have been tested on the release, reuptake and net uptake of noradrenaline (NA) in isolated splenic nerve granules. Cytidine, inosine, and uridine triphosphate facilitated uptake of NA to a similar degree as adenosine diphosphate but less than adenosine triphosphate. Cyclic AMP had no effect. Various inhibitors of the respiratory chain and oxidative phosphorylation (rotenone, chlorpromazine, antimycin and oligomycin) inhibited both release and uptake of NA at 10–3–10–4 M. Atractylate had no action at 10–3 M. Cyanide and azide at 10–3 M had no or a slight action only. The uncouplers dinitrophenol, carbonyl cyanide m‐chlorophenyl hydrazone, desaspidin, and pentachlorphenol all increased the release rate of NA from granules and inhibited reuptake. The results suggest that the ATP facilitated uptake process requires electron transport and that the ability of the granules to retain bound NA is dependent on an energized state of the system. At least certain steps of electron transport‐coupled phosphorylation occurring in mitochondria appear to be involved in amine release and uptake in granules. © 1969 Scandinavian Physiological Society